Pharmacotherapy of Heart Failure
PST 06106
Basic Pharmacotherapy
Session 25: Pharmacotherapy of Heart Failure
Learning Objectives
By the end of this session students are expected to be able to:
Define heart failure
Explain pathophysiology of heart failure
Explain the clinical presentation of heart failure
Outline diagnosis of heart failure
Describe pharmacological treatment of heart failure
Describe the monitoring of heart failure therapy
Activity: Buzzing
What is Heart Failure?
Definition of Heart Failure
Heart failure is a progressive clinical syndrome that can result from any abnormality in cardiac structure or function that impairs the ability of the ventricle to fill with or eject blood, thus rendering the heart unable to pump blood at a rate sufficient to meet the metabolic demands of the body.
It is the final common pathway for numerous cardiac disorders, including those affecting the pericardium, heart valves, and myocardium.
Diseases that adversely affect ventricular diastole (filling), ventricular systol(Contraction), or both can lead to heart failure
Heart Failure is characterized by typical symptoms (e.g. breathlessness, ankle swelling and fatigue) that may be accompanied by signs (e.g. elevated jugular venous pressure, pulmonary crackles and peripheral oedema) caused by a structural and/or functional cardiac abnormality, resulting in a reduced cardiac output and/or elevated intracardiac pressures at rest or during stress
Definition of Heart Failure Cont…
Heart Failure is characterized by typical symptoms (e.g. breathlessness, ankle swelling and fatigue) that may be accompanied by signs (e.g. elevated jugular venous pressure, pulmonary crackles and peripheral oedema) caused by a structural and/or functional cardiac abnormality, resulting in a reduced cardiac output and/or elevated intracardiac pressures at rest or during stress
Heart failure can result from any disorder that affects the ability of the heart to contract (systolic function) and/or relax (diastolic dysfunction)
Therefore, Heart Failure can be;
Systolic Heart Failure or/and
Diastolic Heart Failure
Definition of Heart Failure Cont…
Heart failure with impaired systolic function (i.e., reduced LVEF) is the classic, more familiar form of the disorder
LVEF (Left ventricular ejection fraction
Common Cause Of Heart Failure
Pathophysiology of Heart Failure
Key components of the pathophysiology of cardiac remodeling are.
Myocardial injury (e.g., myocardial infarction) results in the activation of a number of hemodynamic and neurohormonal compensatory responses in an attempt to maintain circulatory homeostasis.
Chronic activation of the neurohormonal systems results in a cascade of events that affect the myocardium at the molecular and cellular levels.
These events lead to the changes in ventricular size, shape, structure, and function known as ventricular remodeling.
The alterations in ventricular function result in further deterioration in cardiac systolic and diastolic function, which further promotes the remodeling process. (LV left ventricular)
Pathophysiology of Heart Failure Cont….
Clinical presentation and diagnosis of HF
General
Patient presentation may range from asymptomatic to cardiogenic shock.
Symptoms
Dyspnea, (Shortness of breath)
Orthopnea (Discomfort when breathed)
Paroxysmal nocturnal dyspnea (an attack of severe shortness of breath and coughing that generally occur at night)
Exercise intolerance
Tachypnea (Fast breathing)
Clinical presentation and diagnosis of HF Cont…..
Symptoms…..
Cough
Fatigue (feeling overtired)
Nocturia (Frequent urination)
Hemoptysis (Coughing up blood)
Abdominal pain
Anorexia
Nausea
Bloating (Build up of gas in the stomach and intestine)
Poor appetite, early satiety
Ascites (Abnominal swelling)
Mental status changes
Clinical presentation and diagnosis of HF Cont…..
Signs
Pulmonary rales (Abnormal lung sound)
Pulmonary edema
Cool extremities
Pleural effusion (build up of fluids between the tissue that line the lungs and the chest)
Tachycardia (Fast heart rate)
Narrow pulse pressure
Clinical presentation and diagnosis of HF Cont…..
Signs…….
Cardiomegaly
Peripheral edema
Hepatojugular reflux (test for measuring jugular venous pressure through the distention of the internal jugular vein)
Hepatomegaly
Clinical presentation and diagnosis of HF Cont…..
Laboratory Tests
Electrocardiogram may be normal, or it could show numerous abnormalities, including acute ST-T wave changes from myocardial ischemia, atrial fibrillation, bradycardia, and left ventricular hypertrophy.
Serum creatinine may be increased due to hypo perfusion.
Preexisting renal dysfunction can contribute to volume overload.
Complete blood count (CBC) can be useful in determining if heart failure is due to a reduced oxygen-carrying capacity.
Clinical presentation and diagnosis of HF Cont…..
Laboratory Tests
…
Chest x-ray: useful for detecting cardiac enlargement, pulmonary edema, and pleural effusions
Echocardiogram: used to assess the size of the left ventricle, valve function, pericardial effusion, wall motion abnormalities, and ejection fraction
Activity: Small Group Discussion
What is the treatment of Heart Failure??
Pharmacological Treatment of Heart Failure
Treatment of Heart Failure of depends on the stage of the Disease
There are four identified stages of heart failure, and their treatment recommendations
Unless contraindicated, all patients with HF-REF(reduced ejection fraction) should be started on an ACE inhibitor and a beta blocker (and a diuretic, in most cases).
No patient should receive three drugs which block the renin-angiotensin-aldosterone system as hyperkalaemia and renal dysfunction will be common.
The safety and efficacy of combining an ACE inhibitor, an ARB and MRA is uncertain and the use of these three drugs together is not recommended
Functional Classification of Heart Failure
Treatment allogarism of Heart failure according to functional stage of Heart Failure
Pharmacological Treatment of Heart Failure Cont….
Beta Blockers
A meta-analysis confirms that beta blockers also reduce mortality in patients with diabetes and HF
All patients with heart failure with reduced ejection fraction,class II-IV, should be started on beta blocker therapy as soon as their condition is stable.
Bisoprolol, carvedilol or nebivolol should be the first choice of beta blocker for the treatment of patients with heart failure with reduced ejection fraction.
If beta blockers are contraindicated consider using ivabradine
Pharmacological Treatment of Heart Failure Cont….
Angiotensin-Converting Enzyme Inhibitors
Patients with heart failure with reduced ejection fraction of all NYHA functional classes, should be given angiotensin-converting enzyme inhibitors.
Important adverse effects are cough, hypotension, renal impairment and hyperkalaemia.
A key but rare adverse effect, which can be life threatening (due to laryngeal involvement), is angioedema.
Any patient who experiences angioedema should have the ACE inhibitor withdrawn immediately and be prescribed an alternative agent.
Pharmacological Treatment of Heart Failure Cont.
….
Angiotensin Receptor Blockers
Angiotensin II type 1 receptor blockers (ARBs) block the biological effect of angiotensin II.
Unlike ACE inhibitors they do not produce cough as a side effect and should be used in patients who cannot tolerate an ACE inhibitor due to cough.
Patients with heart failure with reduced ejection fraction, NYHA class II-IV, who are intolerant of angiotensin-converting enzyme inhibitors should be given an angiotensin receptor blocker.
An angiotensin receptor blocker in addition to an angiotensin-converting enzyme inhibitor should be considered in patients with heart failure with reduced ejection fraction NYHA class II-IV, who are unable to tolerate a mineralocorticoid receptor antagonist.
Pharmacological Treatment of Heart Failure Cont.….
Mineralocorticoid Receptor Antagonists
Patients with heart failure with reduced ejection fraction who have ongoing symptoms of heart failure, NYHA class II-IV, LVEF ≤35%, despite optimal treatment, should be given mineralocorticoid receptor anatgonists unless contraindicated by the presence of renal impairment (chronic kidney disease stage ≥4–5) and/or elevated serum potassium concentration (K+ >5.0 mmol/l).
Eplerenone can be substituted for spironolactone in patients who develop gynaecomastia.
Pharmacological Treatment of Heart Failure Cont.….
Angiotensin Receptor/Neprilysin Inhibitors
Patients with heart failure with reduced ejection fraction who have ongoing symptoms of heart failure, NYHA class II-III, LVEF ≤40% despite optimal treatment should be given sacubitril/valsartan instead of their ACE inhibitor or ARB, unless contraindicated.
It may be considered in patients with NYHA class IV symptoms.
If the patient is already on an ACE inhibitor, the ACE inhibitor should be stopped for 36 hours before initiating sacubitril/valsartan to minimise the risk of angioedema.
Patients should be seen by a heart failure specialist with access to a multidisciplinary heart failure team before starting treatment with sacubitril/valsartan
Pharmacological Treatment of Heart Failure Cont.….
Diuretics/ Loop Diuretics
In the majority of patients with heart failure fluid retention occurs, causing ankle oedema, pulmonary oedema or both, contributing to the symptom of dyspnoea.
Diuretic treatment relieves oedema and dyspnoea.
Patients with heart failure and clinical signs or symptoms of fluid overload or congestion should be considered for diuretic therapy.
The tendency of loop diuretics to cause hypokalaemia is offset by ACE inhibitors, ARBs and spironolactone.
Pharmacological Treatment of Heart Failure Cont.….
Diuretics/ Loop Diuretics …
Care should be taken to select the dose of the loop diuretic on an individual basis, so that the dose chosen or reached should eliminate ankle or pulmonary oedema without dehydrating the patient and placing them at risk of renal dysfunction or hypotension.
The dose of diuretic should be individualised to reduce fluid retention without overtreating which may cause dehydration or renal dysfunction.
Pharmacological Treatment of Heart Failure Cont.….
Digoxin
Digoxin is usually only reserved for patients with severe HF who have not responded to other treatment
In patients with HF and sinus rhythm, digoxin may reduce symptoms and hospital admission
Digoxin should be considered as an add-on therapy for patients with heart failure in sinus rhythm who are still symptomatic after optimum therapy.
If excessive bradycardia occurs with concurrent beta blockade and digoxin therapy, digoxin should be stopped.
Pharmacological Treatment of Heart Failure Cont.….
Hydralazine and Isosorbide Dinitrate
The combination of hydralazine and isosorbide dinitrate (H-ISDN) was shown to reduce mortality in patients with HF before ACE inhibitors were introduced
Patients who are intolerant of an angiotensin-converting enzyme inhibitor and an angiotensin II receptor blocker due to renal dysfunction or hyperkalaemia should be considered for treatment with a combination of hydralazine and isosorbide dinitrate.
Patients with heart failure with reduced ejection fraction, NYHA class III or IV, should be given hydralazine and isosorbide dinitrate in addition to standard therapy
Monitoring of Heart failure Therapy
Monitoring parameters for patients with Heart Failure focuses on three general areas:
evaluation of functional capacity,
evaluation of volume status, and
Laboratory evaluation.
Assessment of volume status is a vital component of the ongoing care of patients with heart failure.
This evaluation provides the clinician important information about the adequacy of diuretic therapy.
Monitoring of Heart failure Therapy Cont…
Because the cardinal signs and symptoms of heart failure are caused by excess fluid retention, the efficacy of diuretic treatment is readily evaluated by the disappearance of these signs and symptoms.
The physical examination is the primary method for the evaluation of fluid retention, and specific attention should be focused on;
the patient’s body weight,
extent of jugular vein distention (JVD),
presence and severity of pulmonary congestion and,
Peripheral edema.
Monitoring of Heart failure Therapy Cont…
Specifically, in a patient with pulmonary congestion, monitoring is indicated for resolution of; rales and pulmonary edema and improvement or resolution of dyspnea on exertion, orthopnea, and Paroxysmal Nocturnal Dyspnea (PND).
Other therapeutic outcomes include an improvement in exercise tolerance and fatigue and a decrease in nocturia and heart rate.
It should be noted that, particularly with
β
-blocker therapy, symptoms may worsen initially and that it may take weeks to months of treatment before patients notice improvement in symptoms.
Routine monitoring of serum electrolytes and renal function is required in patients with heart failure.
Monitoring of Heart failure Therapy Cont…
Assessment of serum potassium is especially important because hypokalemia is a common adverse effect of diuretic therapy and is associated with an increased risk of arrhythmias and digoxin toxicity.
Serum potassium monitoring is also required because of the risk of hyperkalemia associated with ACE inhibitors, ARBs, and aldosterone antagonists.
Assessment of renal function (BUN and serum creatinine) is also an important end point for monitoring diuretic and ACE inhibitor therapy
Key Points
Heart Failure is characterized by typical symptoms (e.g. breathlessness, ankle swelling and fatigue)
Other signs of Heat Failure include elevated jugular venous pressure, pulmonary crackles and peripheral oedema which are caused by a structural and/or functional cardiac abnormality, resulting in a reduced cardiac output and/or elevated intracardiac pressures at rest or during stress
Treatment of Heart Failure of depends on the stage of the Disease
Monitoring parameters for patients with Heart Failure focuses on three general areas which are evaluation of functional capacity, evaluation of volume status, and Laboratory evaluation
Evaluation
What is Heart Failure?
What is the pathophysiology of
Heart Failure?
What are the signs and symptoms of Heart Failure?
How is the treatment of Heart Failure
References
Wells BG, DiPiro J, Schwinghammer T (2013),
Pharmacotherapy Handbook
(6
th
Ed). New York, NY: McGraw-Hill.
DiPiro JT, Talbert RL, Yee GC, Matzke GR, Wells BG, Posey ML, (2008):
Pharmacotherapy: A Pathophysiologic Approach
(7
th
ed): New York, NY: McGraw-Hill.
Katz M D., Matthias KR., Chisholm-Burns M A., Pharmacotherapy(2011)
Principles & Practice Study Guide: A Case-Based Care Plan Approach
: New York, NY: McGraw-Hill.
Schwinghammer TL, Koehler JM (2009)
Pharmacotherapy Casebook: A Patient-Focused Approach
(7
th
ed): New York, NY: McGraw-Hill.
Unataka kutumiwa notes hizi kupitia WhatsApp?Kwa notes zilizopangiliwa vizuri kwa kusoma offline au PDF, bonyeza kitufe hapa chini. Ujumbe wenye Level, Semester, Module na Topic utaandaliwa moja kwa moja.TUMIWA NOTES WHATSAPP
